Adjustable axial seal for regenerative heat exchanger



March 1954 I J w. E. HAMMOND ET AL 2, 70,934

ADJUSTABLE AXIAL SEAL FOR REGENERATIVE HEAT EXCHANGER Filed Oct. 12, 1950 $4 11 T 16 :27 23 Q 2/ 20 H T 2 I2 l u I I I '0 i 3/ 1 V v 3 i I] l/EL a w I Q E l l j a 3,2; 77/ II E 6W0 pur: I 22 I I g I L M l z zm gvroxs d BY ga /0% .r-aazm 22 57 21 ATTORNEY Patented Mar. 2, 1954 3 f UNITED STATES PATENT 10F F ICE ADJUSTABLE AXIAL SEAL FOR REGENERA- rrvn HEAT EXCHANGER x4 Cla-ims. 1

Thepresent invention relates to :improved seal-s for use between th'e'rotor and its enclosing-housing in a rotary regenerative air preheateror similar apparatus.

In a rotary regenerative heater ofthe Ljun'gs'trom type a cyl-indrical rotor has compartments carrying'heat'tran'sfer material which as the rotor turns is firs't exposed to heating gases and then disposedin the air passage to impartthe absorbed heat to'the air. The rotor is enclosed in a housing having end plates formed with circumferentially spaced openings to provide *for "the flow *of gas and air. To prevent the mingling oi the two fluids 'thep'artitions that form the rotorcom- 'partments are provided "with radial sealswhich wipeagainst the imperiorateportions of the end plates between the openings provided for gas :and air iiow, or vice versa. '-In order to -prec1udebypassing of gas a'nd air around the rotor through the clearance space'between the sides-.of the rotor :Figure 1 is .a sectional .elevational view in dia- :grammatic form of arotary regenerative air preheater embodying the present invention.

liigure'z is a broken away view On an enlarged :scale showing the relationship between -the :rotor, the housing and one of the'axia'l seals.

Figure 3 is .a sectional 'iview .on enlarged scale illustrating thesmountingofzone ofitheraxial seals in cooperative relation between the housing and the rotor together with :one of'theadjustin'g means therefor. I

In the drawings'the numeral l t designates the cy'lindrical shell of a rotor divided into sector shaped compartments by radial partitions -;con-

necting it with the rotor post 12 whichis driven bya motor-and reduction'gearing F3 to turn the rotor slowly about its axis. The rotor compart ments contain regenerative heat transfer material in the form of-closelyspaced metallic lates t] *whichfirst abs'orb 'hee't from hot'gases enter- The invention will William E. Hammond, Wellsville, and Clayton-A. Ballard, Belmont, N. Y.-,'assignors 'to The Air Preheater 'Gorporation, New York, N. 1.

Application Butcher .12, 1950, Serial 'No. 189;757

ing the preheater through a duct "55 from :a boiler brother source to be discharged after passing over the heat transfer plates 1 l through an'outlet duct It to which an induced draft fan :(not shown) is connected. As the rotor turns slowly about its axis, the heated plates 14 are moved intothe stream-of air admitted through the duct 17 to which 'a forced draft lan (not shown) is connected. After pass'ingover the plates all and absorbing heat therefrom the stream of air is conveyed to the boiler furnace or other place of use through duct 18.

A housing =2 0 enclosing the rotor H! is provided eit either end'opposite the latter'with end or sector plates 21 which are 'apertured at 22 "and 23 in circumierentia'lly spaced locations to admit and discharge streams of gas and air flowing through 'the rotor. In order that the-streams of gas and air may not commingle,'the end plates "2| have imperiorate portions 24 between the gas and air openings at least -'equal to but usually greater in circumferential extent than one rotor-compartment for engagement by the radial-seals indicated at 2-5 to isolate or block off at least one compartment when positioned between the gas and air ipassages. In order that "the streams of gas "and air may not by-pass the heat transfer surface H *by flowing axially in the annular clearance space "26 between the 'rotor'shell it and thehousing '20 it is customary to provide circumferential seals indicated diagrammatically at t2! "on the shell W which wipe against confronting :parts or "the find plates "21 *or allied parts so as to sea'l'off the space 26.

"vided extending between the 'rotor and fhOllSllTg to prevent leakage chair to the gas side around the rotor 18 in the space :25, these 'being addition to the usualiradial seals "25 that preclude leakage across "the ends of the rotor from the air to the lgaspassage. The omission of the .011"- cum'ferential seal heretofore conventionally provided at the hot end of the preheater permits the entering hot gas and the heatedair to flow into the space 26 around :thelrotoriso as :tomain- .tain parts of the rotor shell 1 ii and nppositeparts of the housing 20 at substantially the same tem- ,perature :so as to minimize relative z'distortion {due :to non-uniform expansion and contraction. As is illustrated in Figures 2 .and :3 sealgni'dmg plates 30, :33] "are :attached'to theshousing Mia-rid extend in :spaced parallel relation in a direction axially of the rotor shell-iii in the space 26 be .able spring actuated flanges 3 5.

3 tween the latter and the inner wall of the housing. The guide plates 30, 3| extend between the upper and lower rotor housing flanges 32 to which the end plates 2| are fixed and are provided with lateral flanges 33 by means of which they may be attached to the wall of the housing 20. The guide plates 38, 3| project inwardly from the inner wall of housing 20 into the space 24 between the housing 20 and rotor shell to a point somewhat short of the latter in locations beneath the imperforate portions of the sector plates 2| so that the seals 34 mounted between them engage the rotor shell 10 to completely seal oif the air passage from the gas passage and preclude leakage around the rotor in the space 24. In the groove between each of the two pairs of guide plates 30, 3| a sealing plate 34 is mounted which has a height coextensive with that of the distance between the flange plates 32 on the housing 2!]. The two sealing members 34 mounted at opposite sides of the rotor, but not necessarily at diametral locations, are each pressed into contact with the outer surface of the rotor shell 10 by several plungers 31 "each biased by a spring 38 carried in a housing 40 mounted on the outside of the rotor housing 20. The space between the guide plates 30, 3| is closed by the cover strip 35 which is provided with a series of slots 36 to accommodate a number of plungers positioned at diiferent locations axiallyof the rotor so that independent adjustments may be effected of these seal strips 34 at :different positions axially of the rotor to accommodate any bulging Or bowing of the rotor or of the enclosing housing. These individual adjustments may be effected by means of the screws 43 associated with the several springs 33.

At the top of the rotor a bafile angle 53 is provided extending circumferentially beneath the sector plate 2| and bafile end pieces 54 are mounted in positions circumferentially spaced in accordance with the locations of the sealing strips 34. There is also provided a baffle plate 55, this serves to reduce radial leakage of air. At the lower end of the rotor a similar bafiie angle 56 is provided and end plates 51'. Here also there is provided a sealing circumferential strip. Also at the hot end of the preheater the end edge of the rotor shell is provided with the sealing strip 58 which limits the amount of fluid that may be bypassed.

Thus, the axial seals 34 extend from the housing flange at the hot end of the preheater to the similar flange at the cold end. The sealing shoes 34 mounted between the retainers 30, 31

on the housing are pressed against the rotor shell 10 by the series of independently adjust- Ihis eifects a complete seal between the air and gas passages and precludes flow therebetween in a direction around the side of the rotor in the space 26 between the latter and the housing. In the way of the sector plates on both ends of the header the baflles 53, 54, 55, 56, 5'! prevent radial leakage of air. I What we claim is:

1. A regenerative apparatus including a rotor comprising a cylindrical shell carrying heat transfer material separated by an annular space from a housing that surrounds the rotor and which is provided opposite the circular ends of the latter with axially spaced upper and lower end plates including imperforate portions located between circumferentially spaced apertures formed in said plates for the flow of heating gases and air to and through the rotor; axial seals mountinto said annular space between the latter and the rotor in spaced relation oircumferentially of the rotor; and a plurality of individually adjustable biasing means associated with each sealing member at points spaced axially of the rotor for biasing the said member into sealing contact with the rotor shell.

2. A regenerative apparatus including a rotor comprising a cylindrical shell carrying heat tran fer material separated by an annular space from a housing that surrounds the rotor and which is provided opposite the circular ends of the latter with-axially spaced upper and lower end plates including imperforate portions located between circumferentially spaced apertures formed in said plates for the flow of heating gases and air to and through the rotor; axial seals mounted in said annular space between the rotor shell and housing in locations confronting and intermediate imperforate portions of said end plates between the flow apertures in the upper and lower end plates each comprising: a pair of guide plates extending parallel to the axis of the rotor from the lower to the upper end plate and projecting from the inner wall of the housing into said annular space between the latter and the rotor in spaced relation circumferentially of the rotor to form an open channel facing the rotor shell; a seal. strip member seated in said channel and projecting therefrom toward the side of the rotor shell; a plurality of individually adjustable biasing springs associated with said sealing member at points spaced axially of the rotor for biasing the said member into sealing contact with the rotor; and individual means for adjusting the biasing force applied by said springs to said axial sealing strips.

3. A regenerative apparatus including a rotor comprising a cylindrical shell carrying heat transfer material separated by an annular space from a housing that surrounds the rotor and which is provided opposite the circular ends of the latter with axially spaced upper and lower end plates including imperforate portions located between circumferentially spaced apertures formed in said plates forthe flow of heating gases and air to and through the rotor; circumferential sealing means between the rotor and housing located at one end of the rotor; axial seals mounted in said annular space between the rotor shell and housin in locations confronting and intermediate imperforate portions of the upper and lower end plates between the flow apertures in said end plates comprising: a pair of sealing members extending parallel to the axis or the rotor from the lower to the upper end plate and projecting fer material separated by an annular space from a housing that surrounds the rotor and which is provided opposite the circular ends of the latter with axially spaced upper and lower endplates including imperforate portions located between circumferentially spaced apertures formed in said plates for the flow of heating gases and air to and through the rotor; circumferential sealing means between the rotor and housing at only the gas inlet and air outlet end thereof: axial seals mounted in said annular space between the rotor shell and housing in locations confronting and intermediate imperforate portions of said end plates between the flow apertures in the upper and lower end plates each comprising: a pair of guide plates extending parallel to the axis of the rotor from the lower to the upper end plate and projecting from the inner wall of the housing into said annular space between the latter and the rotor and disposed in spaced relation circumferentially of the rotor to form an open slot facing the rotor shell; a seal strip member seated in said slot and projecting therefrom toward the side of the rotor shell; a plurality of individually adjustable biasing means associated with said sealing member at points spaced axially of the rotor for biasing the said member into sealing contact with the rotor; and individual means for adjusting the biasing force applied to said axial sealing strips.

WILLIAM E. HAMMOND.

CLAYTON A. BALLARD.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 2,287,777 Boestad June 30, 1942 2,337,907 Lundstrom Dec. 28, 1943 2,347,829 Karlsson et a1. h--- May 2, 1944 2,480,248 Karlsson et al. Aug. 30, 1949 FOREIGN PATENTS Number Country Date I 970,696 France June 21, 1950 

